The Tissue Culture/Media facility is composed of two parts as follows: The Tissue Culture Facility houses eight incubators, three biological safety cabinets, a large capacity centrifuge, microscopes, Coulter counter, seven cryogenic storage tanks, and all other equipment required for the growth of animal cells. Services include the production, dispensation, and testing of tissue culture media and supplements. The facility does large-scale production of cells necessary for enzyme isolation for the DNA core research directed by Dr. Linn. Insect and mammalian cells are grown for transfection and expression of protein for the laboratories of Drs. Linn and Ames. Mammalian cells are grown and experiments done by facility personnel for aging, antioxidant, and folate deficiency studies for research in the Ames laboratories. Hybrodomas are grown to produce antibodies used in the laboratories of Drs. Ames, Linn, and Rine. Training is provided by the director to students and postdoctoral fellows who wish to learn cell culture techniques. Up to 95% of the monthly use of the facility is by Center members, particularly the laboratories of Drs. Ames, Linn, and Rine. The two Media Facilities produce sterile media and plates utilized in the growth of microorganisms. They are equipped with three large autoclaves, three media dispensing pumps, two automatic plate pouring machines, several balances, and other small equipment. Services include the production of the petri plates used for toxicity and mutagenicity tests and in studies of the transport and metabolism of mutagenic agents. The facility also provides liquid media for the growth of large quantities of bacteria and yeast utilized by many of the research core subunits. Heavy users of the media provided by these facilities include the laboratories of Drs. Ames, Botchan, Cozzarelli, Rine and M. Smith. Services are provided on a recharge basis ($14/hour labor) and records of usage are maintained by staff in the MCB department.